I think this is self explanatory to say but, if the ad poster isn't well reviewed don't do a deposit or e transfer, if needed try for in person only, if they refuse with some bs story it's usually a scammer
also only-fans ads are usually a tell told sign + using telegram + whats-app and if you scroll down and see multiple ads from the same poster click one if shows another town far away 100 percent scammer, also try to google lens or tineye the images see if it comes back with a hit somewhere else.